The energy management for integrated circuits in customer-specific applications is increasingly faced with the task of being able to satisfy a continuously rising power demand. In particular, modern processors require high currents that must be made available via power supply rails of several DC/DC down converters. Accordingly, the control circuits (power management units) required for this purpose are becoming more and more complex, such that the expenditures for making available high currents increase accordingly. Limiting factors in this respect are, for example, the size of the semiconductor substrate used, the number of pins and terminals, thermal restrictions due to power losses, as well as restrictions due to the current conduction and the limited soldering space.
In the prior art, it is known to utilize external transistors in order to reduce the complexity of integrated circuits for energy management and to simultaneously make available high currents. In this way, the supply path (power path) can be separated from the central control unit (power management integrated circuit or PMIC). Although the utilization of external transistors allows a simpler design of the PMICs, this arrangement has a number of disadvantages. For example, multiple terminals (pins) are required for implementing a conventional current mode DC/DC converter (current mode). Furthermore, currently available external transistors only have a low switching frequency and therefore slow rise and fall times. This makes it necessary to utilize coils with higher impedance that further reduce the efficiency of the DC/DC converter. This may be particularly critical in applications with processors that require a plurality of power supplies. There is a need in the art for a converter arrangement with reduced complexity, as well as the capability of making available high currents.